Protein Synthesis

Transcription is where one strand of the DNA acts as a template for the production of mRNA, a complementary section of part of the DNA sequence. This occurs in the nucleus.

Translation is where the mRNA acts as a template to which complementary tRNA molecules attach, and the amino acids they carry are linked to form a polypeptide. This occurs on the ribosomes in the cytoplasm.

Transcription

DNA doesn't leave the nucleus. Transcription is the process whereby part of the DNA, the gene, acts as a template for the production of mRNA, which carries information needed for protein synthesis from the nucleus to the cytoplasm. Ribosomes in the cytoplasm provide a suitable surface for the attachment of mRNA and the assembly of protein. This is the sequence of events:

The enzyme DNA helicase breaks the hydrogen bonds between the bases in a specific region of the DNA molecule, causing the two strands to separate and unwind, exposing the nucleotide bases.

The enzyme RNA polymerase binds to the template strand of the DNA at the beginning of the sequence to be copied.

Free RNA nucleotides align opposite the template strand, based on the complementary relationship between the bases in DNA and the free nucleotides.

RNA polymerase moves along the DNA forming bonds that add RNA nucleotides, one at a time, to the growing RNA strand. This results in the synthesis of a molecule of MRNA alongside the unwound portion of DNA. Behind…